GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Catera 🢒 Body and Accessories 🢒 Lighting Systems 🢒 Courtesy Lamps Inoperative

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

DEFINITION: One or all of the following courtesy lamps are inoperative: the front side door courtesy lamps, rear side door courtesy lamps, roof rail courtesy lamps, and dome lamp.

1

Did you perform the Lighting System Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2
  1. Turn the ignition switch to the RUN position.
  2. Pull the interior lamps switch in order to turn ON the interior lamps:
  3. Verify that the courtesy lamps are inoperative with the interior lamp switch ON.

Are all the courtesy lamps operating properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Determine if all the following lamps are inoperative from the headlamp switch:

    • Dome lamp
    • Front door courtesy lamp
    • Roof rail courtesy lamp

Are all of these lamps inoperative from the headlamp switch?

Go to Step 4

Go to Step 10

4
  1. Turn ignition switch to the RUN position, with the engine OFF.
  2. With a scan tool, observe the courtesy switch input data.
  3. Pull the interior lamps switch in order to turn ON the interior lamps.

Does the scan tool indicate that the courtesy switch input parameter changes when the interior lamp switch is pulled?

Go to Step 7

Go to Step 5

5

Test for an open or high resistance in the Interior lamp switch signal circuit (XY112). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 6

6

Test for an open high resistance in the Interior lamp switch ground circuit (F18). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 29

7

Test for an open or high resistance in multifunction relay K134 ground circuit (F805). Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 8

8

Test for an open or high resistance in the courtesy lamps supply voltage circuit (AP805) of the multifunction relay K134. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 9

9

Test for an open or high resistance in the courtesy lamps ground circuit (XP803) of the multifunction relay K134 . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 28

10

Determine which courtesy lamps are inoperative with the interior lamp switch on.

Are the LH and/or RH front side door courtesy lamps inoperative?

Go to Step 11

Go to Step 13

11
  1. Determine which front side door courtesy lamps are inoperative.
  2. Test for an open or high resistance in the inoperative front side door courtesy lampr supply voltage circuit . Refer to Circuit Testing and in Wiring Repairs Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 12

12

Test for an open in the inoperative front side door courtesy lamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 27

13
  1. Place the roof rail courtesy lamp switch in the center position.
  2. Determine if the courtesy lamps are inoperative.

Are the RH and/or LH roof rail courtesy lamps inoperative?

Go to Step 14

Go to Step 16

14
  1. Determine which roof rail courtesy lamps is inoperative.
  2. Test for an open or high resistance in the inoperative roof rail courtesy lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 15

15

Test for an open in the inoperative roof rail courtesy lamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 25

16
  1. Push the headlamp switch in order to turn OFF the interior lamps.
  2. Turn ON the roof rail courtesy lamp switches by pressing the switch toward the front of the vehicle.

Are the RH and/or LH roof rail courtesy lamps inoperative with the roof rail courtesy lamp switches ON?

Go to Step 17

Go to Step 18

17

Test for an open in the inoperative roof rail courtesy lamp switch ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 25

18
  1. Open the LH rear side door and observe the LH rear side door courtesy lamp.
  2. Open the RH rear side door and observe the RH rear side door courtesy lamp.
  3. Verify which courtesy lamp is inoperative.

Are the RH and/or LH rear side door courtesy lamps inoperative?

Go to Step 19

Go to Step 22

19
  1. Determine which rear side door courtesy lamp is inoperative.
  2. Test for an open or high resistance in the inoperative rear side door courtesy lamp supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 20

20

Test for an open in the inoperative rear side door courtesy lamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 30

Go to Step 21

21
  1. Disconnect the inoperative rear side door courtesy lamp.
  2. Open the rear door with the inoperative courtesy lamp.
  3. Probe the inoperative courtesy lamp ground circuit with a test lamp that is connected to B+.

Does the test lamp illuminate?

Go to Step 27

Go to Step 24

22

If the dome lamp is inoperative, locate and repair an open or a high resistance in the dome lamp supply voltage circuit.

Did you find and correct the condition?

Go to Step 30

Go to Step 23

23

Locate and repair an open or a high resistance in dome lamp ground supply circuit.

Did you find and correct the condition?

Go to Step 30

Go to Step 26

24

Replace the inoperative door jamb switch. Refer to Door Jamb Switch Replacement .

Is the repair complete?

Go to Step 30

--

25

Replace the roof rail courtesy lamp switch. Refer to Roof Side Rail Lamp Replacement .

Did you find and correct the condition?

Go to Step 30

--

26

Replace the dome and reading lamp. Refer to Dome Lamp Replacement .

Did you complete the repair?

Go to Step 30

--

27

Replace the inoperative side door lamp. Refer to Ashtray Lamp Replacement .

Is the repair complete?

Go to Step 30

--

28

Replace the multifunction relay K134.

Is the repair complete?

Go to Step 30

--

29

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the repair complete?

Go to Step 30

--

30
  1. Connect all the connectors and components that were disconnected.
  2. Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2